This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision | Next revision Both sides next revision | ||
|
teaching:projh402 [2020/10/03 14:11] ezimanyi [K-D-Tree Indexes for MobilityDB] |
teaching:projh402 [2020/10/03 14:11] ezimanyi [K-D-Tree Indexes for MobilityDB] |
||
|---|---|---|---|
| Line 79: | Line 79: | ||
| Indexes are essential in databases for quickly locating data without having to search every row in a table every time a database table is accessed. Thus, an index is an auxiliary data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and storage space to maintain the index. PostgreSQL provides [[https://habr.com/ru/company/postgrespro/blog/441962/|multiple types of indexes]] for various data types. | Indexes are essential in databases for quickly locating data without having to search every row in a table every time a database table is accessed. Thus, an index is an auxiliary data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and storage space to maintain the index. PostgreSQL provides [[https://habr.com/ru/company/postgrespro/blog/441962/|multiple types of indexes]] for various data types. | ||
| - | In MobilityDB two types of indexes has been implemented, [[https://habr.com/en/company/postgrespro/blog/444742/|GiST]] and [[https://habr.com/ru/company/postgrespro/blog/446624/||SP-GiST]]. More precisely, in PostgreSQL, these types of indexes are frameworks for developing multiple types of indexes. Concerning SP-GiST indexes, in MobilityDB we have developed 4-dimensional quad-trees where the dimensions are X, Y, and possibly Z for the spatial dimension and T for the time dimension. An alternative approach would be to use [[https://en.wikipedia.org/wiki/K-d_tree|K-D Trees]]. K-D trees can be implemented in PostgreSQL using the SP-GiST framework and an example [[https://github.com/postgres/postgres/blob/master/src/backend/access/spgist/spgkdtreeproc.c|implementation]] for simple [[https://www.postgresql.org/docs/current/datatype-geometric.html|geometric types]] exist. The goal of the project is to implement K-D indexes for MobilityDB and perform a benchmark comparison between K-D trees and the existing 4-dimensional quad-trees. | + | In MobilityDB two types of indexes has been implemented, [[https://habr.com/en/company/postgrespro/blog/444742/|GiST]] and [[https://habr.com/ru/company/postgrespro/blog/446624/|SP-GiST]]. More precisely, in PostgreSQL, these types of indexes are frameworks for developing multiple types of indexes. Concerning SP-GiST indexes, in MobilityDB we have developed 4-dimensional quad-trees where the dimensions are X, Y, and possibly Z for the spatial dimension and T for the time dimension. An alternative approach would be to use [[https://en.wikipedia.org/wiki/K-d_tree|K-D Trees]]. K-D trees can be implemented in PostgreSQL using the SP-GiST framework and an example [[https://github.com/postgres/postgres/blob/master/src/backend/access/spgist/spgkdtreeproc.c|implementation]] for simple [[https://www.postgresql.org/docs/current/datatype-geometric.html|geometric types]] exist. The goal of the project is to implement K-D indexes for MobilityDB and perform a benchmark comparison between K-D trees and the existing 4-dimensional quad-trees. |